Yarn finishing



July 27, 1943. v. R..HARDY YARN FINISHING Filed Nov. 1, 1941 ATTORNEY h0 I I L r:

INVENTOR Vg rwa .4 Hard Liquid Level before openzf/bn 5/ Patented July27, 1943 UNITED .STATES PATENT OFFICE YARN FINISHING Vernal R. Hardy,Wilmington, Del., alsignor to E. I. du Pont de N emom's & Company,Wilming ton, DBL,

a corporation of Delaware Application November 1, 1941, serial No.417,431

5 Claims.

This invention relates to yarn finishing, and more particularly itrelates to an apparatus for uniformly applying a liquid, such as a sizeor "all showing several modified forms of liquid applicators;

Figure 9 is a perspective view showing still another modifled formoi'liquid applicator.

Referring to Figures 1 and 2 of the drawing, reference numeral Hdesignates a reservoir for a liquid. The reservoir H contains a slot l3into which. a liquidv applicator I! may be positioned,

In the application of liquids to yams,- it is I known to cause the yarnto pass over devices contacting in one of several ways a pool of theliquid to be applied to the yarn. It is known, for example, to run theyarn over a wick dipping into the liquid and to depend on capillarity tokeep the operating portion of the wick constantly and uniformly suppliedwith the liquid. Wicks,

however, are notorious for being undependable when small and strictlyuniform qualities of liquid are to be applied, with the result that verycomplicated mechanical'devices have been employed for the purpose. Thisis probably due to the fact that the capillary passages of a wick are ofunknown shapes and dimensions.

It is an object of the present invention to provide an apparatus forapplying to a yarn, passing in contact therewith, a dependably uniformquantity of liquid over very long periods of time.

Other objects of the invention will appear hereinafter.

The objects of this invention are accomplished, in general, by anapparatus comprising a liquid reservoir, a liquid applicator projectingfrom within said reservoir, said applicator comprising solid confiningwalls about a capillary passage of a predetermined given size which willdraw the liquid from the reservoir to the yarn passing in contact withthe liquid in the capillary passage.

The details of the apparatus of the present invention will be moreclearly understood by reference to the following detailed descriptionwhen taken in connection with the accompanying illustrations, in which:

Figure 1 is a perspective view of one form of liquid applying apparatusconstructed 'in accordance with the present invention;

Figure 2 is a front elevational view of the apparatus shown in Figure1;'

Figure 3 is a side elevational view of a modified form of liquidapplying apparatus;

Figure 4 is a front elevational view paratus shown in Figure 3;

Figures 5, 6, 7 and 8 are front elevational views,

of the ap- Jects from withinthe reservoir The liquid may be circulatedthrough the reservoir II by means of inlet opening I5 and outlet openingI1. The liquid applicator I! which prois comprised of two substantiallyparallel plates 2l and 23. A V shaped groove 22 is cut transverselyacross the top of the plates. The sides of the plates are sealed bymeans of elements 25, which may' consist of sealing wax-or small spacingelements. A pair of spacing elements 21 and 29 are positioned betweenplates 2| and 23 so as to maintain a capillary passage between theplates of a predetermined given size. The spacers 21 and 29 will have athickness such that the liquid willrise in the capillary passage betweenthe plates to at least the bottom of the V shaped groove 22. Preferably,the spacers will be of such thickness that the liquid will rise tocompletely fill the capillary passagebetween the said plates 21 and 23.A pair ofyarn guides 33 and 35 are positioned to guide the yarn 3| intocontact with the bottom of the V shaped groove 22, and, therefore, incontact with the liquid in the capillary passage between the plates. Theyarn passing through guides 33 and 85 will pick up a constant anduniform amount of liquid from the capillary passage, the capillarypassage continuing to draw liquid from the reservoir to the Referring tothe modification shown in Figures 3 and 4 of the drawing, a pair ofsubstantially parallel plates 43 and 45 are maintained in spacedrelationship to each other by means of spacer 41. The spacing will besuch that the. liquid is caused to rise from the reservoir II to a linedesignated in the drawing as the liquid level before operation." In thismodification of the invention, the edges of the plates are not sealed asin the modification shown in Figures 1 and 2. The liquid applicator inthis modification is provided with a pair of yarn guiding elements 49and 55. These elements will aid in maintaining the plates 43 and 45 infixed spaced relation to each other.

As shown in Figure 3, the yarn 3| is passed between the spaced platesand within the capillary passage between the plates by passing the yarnabout elements 49 and I5; The applicator is provided with fixed wings 5|and 53, as shown in Figure 4. The applicator may be rigidly fixed to thereservoir by means of bolts passing through these wings.

In this modification of the invention, the yarn passing between theplates will lower the liquid level in the capillary passage to theapproximate line shown in the drawing as "liquid level in operation. Thecontinued passage of the yarn through the applicator capillary passagewill apply to the yarn a constant uniform quantity of liquid which itcontinues to draw from the reservoir H.

The liquid applicator I9a, shown in Figure 5, is similar to theapplicator l9 shown in Figures 1 and 2 except that a small notch 65 iscut in the bottom of the V shaped groove. Under certain circumstances,it is found that such a small notch will apply a liquid to all sides ofa yarn passing therethrough.

In the modified form of applicator shown in Figure 6, the fine notch 63is cut transversely across the tops of the parallel plates. This finenotch will function in substantially the same manner as the notch 65 inthe bottom of the V shaped groove 22 shown in Figure 5.

The modification shown in Figure '7 is substantially the same as thatshown in Figure 6 except that the fine notch BI is positioned at anangle to the vertical.

In the modification shown in Figure 8, the yarn is passed through asmall circular hole 61 cut through the two plates. The yarn passingthrough the small hole 61 will contact the liquid in the capillary.

Figure 9 of the drawing illustrates a form of capillary tube suitablefor use in accordance with the present invention. The capillary tube IIis provided with a V shaped groove 13 transversely across the topthereof and the small capillary, opening 15 passes through the center ofthe tube and connects with the bottom of the V shaped groove. Yarnpassing through, in contact with the bottom of the V shaped groove 13,will pick up a constant uniform quantity of liquid from reservoir 11.

The liquid applicator may have substantially any desired form or shape.Furthermore the side walls of the applicator may be made of anyconvenient thickness to serve as a bearing surfacefor the yarn. Thecapillary passage must, of course, have such a dimension that the liquidwill be drawn thereby from the reservoir to the point of contact of theyarn with the capillary passage. The capillary passage need notnecessarily be of uniform shape and cross section. However, it should beof such a predetermined given size as to apply to the yarn the properquantity of liquid in constant and uniform application. The particularsize and shape of the capillary passage and external confining walls maybe adjusted to suit the viscosity, surface tension of the liquid, thetemperature of the operation, the amount of liquid to be applied,relatiVe to the speed of the thread, as desired by anyone skilled in theart. Such adjustments will be obvious to an operator, once the desiredrate of liquid application is established.

The confining walls of the capillary passage may be made of any desiredmaterial, for example, they may be composed of corrosion-resistantmetals, glass, porcelain, rubber, resins, or any other desired material.In one embodiment of liquid applicator, which has been found to functionvery well in applying a tannic acid subcoating to a synthetic linearpolyamide yarn, the applicator was comprised of two glass plates havingthe approximate thickness of microscope slides. These two glass plateswere spaced from each other by the insertion therebetween of two glassspacers 0.006 inch thick. The glass spacers were comprised of microscopecover glasses. The glass plates were held together with spacerstherebetween by means of sealing wax. The glass plates wereapproximately three-quarters of an inch in height and containedtransversely across the top thereof a 60 V groove, three-sixteenths ofan inch deep. The structure was maintained in a holder and positioned sothat the bottom of the assembly projected into the liquid.

The quantity of liquid (per cent based on the weight of the yarn) whicha capillary applicator of the type herein disclosed will apply to a yarnor thread is dependent upon the size of the capillary, the speed of theyarn, the character of the liquid, and somewhat upon the size of theyarn and the twist in the yarn. In order to apply a uniform quantity ofliquid to a yarn with the apparatus of the present invention, it is, ofcourse, necessary that the yarn be passed tautly in contact with theapplicator, otherwise, the yarn may move from its proposed path oftravel and thus cause spotty application of the liquid. The amount ofsolid applied to the yarn from a solution or emulsion can be varied forany given apparatus by changing the concentration of the solution oremulsion.

The apparatus of the present invention may be used for the applicationof any liquid solution or emulsion to a yarn, thread, or the like. Forexample, it may be used for the application of oils, dyes, finishes,antistatic agents, sizes, coating compositions, and the like.

The apparatus of the present invention may be used for the applicationof liquids to substantially any type of filamentous structure, such asyarns, threads, cords, ropes, or filaments.

It will be obvious that the device may be used to apply liquid to yarnin combination with any operation where the yarn runs from one positionto another, such as on a spinning machine, coning machine, sizingmachine, uptwister, downtwister, skein winder, warper, slasher, spooler,or knitting machine.

By means of the apparatus of the present invention, liquids may beapplied to the yarns and the like in a simple, dependable manner, andwith a high degree of position-to-position and day-to-day uniformity.The apparatus of the present invention is found to be capable of moreuniform and constant application of liquids than previously knownapplicating devices, such as wicks. This is probably due to the factthat capillary passages in wicks are of unknown and indeterminate sizeand shape, whereas the capillary passages of the present invention areof predetermined given size. It has furthermore been found that theapparatus of the present invention has particular advantage overpreviously known liquid applicating devices in that a position may bestarted after a long period of inaction without any startingdifiiculties and the yarn first led into contact with the applicatingdevice of the present invention may be put into regular production.

Since it is obvious that many changes and modifications can be made inthe details above described without departing from the nature and spiritof the invention, it is to be understood that the invention is not to belimited to these details except as set forth in the appended claims.

I claim:

1. Apparatus for applying a liquid to a yarn which comprises areservoir, a liquid applicator projecting from within said reservoir,said applicator comprising solid confining walls about'a capillarypassage of a predetermined given size, said capillary passage adapted todraw the liquid from the reservoir solely by means of capillaryattraction, and means for guiding said yarn across the upper surface ofsaid confining walls into contact with the liquid in said capillarypassage.

2. Apparatus for applying a liquid to a yarn which comprises areservoir, a liquid applicator projecting from within said reservoir,said applicator comprising solid confining walls about a capillarypassage of a predetermined given size, said capillary passage adapted todraw the liquid from the reservoir solely by means of capillaryattraction, and groove means in the upper surface of said confiningwalls for guiding said yarn across said capillary passage into contactwith the liquid in said capillary passage.

3. Apparatus for applying a liquid to a yarn which comprises areservoir, a liquid applicator projecting from within said reservoir,said applicator comprising solid confining walls about a capillarypassage of a predetermined given size, said capillary passage adapted todraw the liquid from the reservoir solely by means of cap-, illaryattraction, and a V shaped groove means in the upper surface of saidconfining walls for guiding said yarn across said capillary passage intocontact with the liquid in said capillary passage.

4. Apparatus for applying a liquid to a yarn which comprises areservoir, a liquid applicator projecting from within said reservoir,said applicator comprising solid confining walls about a capillarypassage of a predetermined given size, said capillary passage adapted todraw the liquid from the reservoir solelv by means of capillaryattraction, and an e, ning through said confining walls forguiding'dfia-id yarn into contact with the liquid in said capillarypassage.

5. Apparatus for applying liquid to a yarn which comprises a reservoir,a liquid applicator projecting from within said reservoir, saidapplicator comprising spaced confining plates about a capillary passageof a predetermined given size,

a groove in said plates connected with said capillary passage, saidcapillary passage adapted to draw liquid from said reservoir to saidgroove solely by means of capillary attraction, and means for passing ayarn in said groove in contact with said liquid in said capillaryPassage.

VERNAL R. HARDY,

